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[PATCH 2/5] RBTX4939: Add MTD support

To: linux-mips@linux-mips.org
Subject: [PATCH 2/5] RBTX4939: Add MTD support
From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Date: Tue, 20 Jan 2009 23:12:16 +0900
Cc: ralf@linux-mips.org, linux-mtd@lists.infradead.org, dwmw2@infradead.org, linux-kernel@vger.kernel.org
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org
Add platform support for NOR flash chips on RBTX4939 board.
This board has complex flash mappings, controlled by its DIPSW setting.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
 arch/mips/include/asm/txx9/rbtx4939.h |    9 ++
 arch/mips/txx9/rbtx4939/setup.c       |  157 +++++++++++++++++++++++++++++++++
 2 files changed, 166 insertions(+), 0 deletions(-)

diff --git a/arch/mips/include/asm/txx9/rbtx4939.h 
b/arch/mips/include/asm/txx9/rbtx4939.h
index 1acf428..e517899 100644
--- a/arch/mips/include/asm/txx9/rbtx4939.h
+++ b/arch/mips/include/asm/txx9/rbtx4939.h
@@ -130,4 +130,13 @@
 void rbtx4939_prom_init(void);
 void rbtx4939_irq_setup(void);
 
+struct mtd_partition;
+struct map_info;
+struct rbtx4939_flash_data {
+       unsigned int width;
+       unsigned int nr_parts;
+       struct mtd_partition *parts;
+       void (*map_init)(struct map_info *map);
+};
+
 #endif /* __ASM_TXX9_RBTX4939_H */
diff --git a/arch/mips/txx9/rbtx4939/setup.c b/arch/mips/txx9/rbtx4939/setup.c
index 74839f2..eee8763 100644
--- a/arch/mips/txx9/rbtx4939/setup.c
+++ b/arch/mips/txx9/rbtx4939/setup.c
@@ -16,6 +16,9 @@
 #include <linux/leds.h>
 #include <linux/interrupt.h>
 #include <linux/smc91x.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/map.h>
 #include <asm/reboot.h>
 #include <asm/txx9/generic.h>
 #include <asm/txx9/pci.h>
@@ -282,6 +285,159 @@ static void rbtx4939_7segled_putc(unsigned int pos, 
unsigned char val)
        __rbtx4939_7segled_putc(pos, val);
 }
 
+#if defined(CONFIG_MTD_RBTX4939) || defined(CONFIG_MTD_RBTX4939_MODULE)
+/* special mapping for boot rom */
+static unsigned long rbtx4939_flash_fixup_ofs(unsigned long ofs)
+{
+       u8 bdipsw = readb(rbtx4939_bdipsw_addr) & 0x0f;
+       unsigned char shift;
+
+       if (bdipsw & 8) {
+               /* BOOT Mode: USER ROM1 / USER ROM2 */
+               shift = bdipsw & 3;
+               /* rotate A[23:22] */
+               return (ofs & ~0xc00000) | ((((ofs >> 22) + shift) & 3) << 22);
+       }
+#ifdef __BIG_ENDIAN
+       if (bdipsw == 0)
+               /* BOOT Mode: Monitor ROM */
+               ofs ^= 0x400000;        /* swap A[22] */
+#endif
+       return ofs;
+}
+
+static map_word rbtx4939_flash_read16(struct map_info *map, unsigned long ofs)
+{
+       map_word r;
+
+       ofs = rbtx4939_flash_fixup_ofs(ofs);
+       r.x[0] = __raw_readw(map->virt + ofs);
+       return r;
+}
+
+static void rbtx4939_flash_write16(struct map_info *map, const map_word datum,
+                                  unsigned long ofs)
+{
+       ofs = rbtx4939_flash_fixup_ofs(ofs);
+       __raw_writew(datum.x[0], map->virt + ofs);
+       mb();   /* see inline_map_write() in mtd/map.h */
+}
+
+static void rbtx4939_flash_copy_from(struct map_info *map, void *to,
+                                    unsigned long from, ssize_t len)
+{
+       u8 bdipsw = readb(rbtx4939_bdipsw_addr) & 0x0f;
+       unsigned char shift;
+       ssize_t curlen;
+
+       from += (unsigned long)map->virt;
+       if (bdipsw & 8) {
+               /* BOOT Mode: USER ROM1 / USER ROM2 */
+               shift = bdipsw & 3;
+               while (len) {
+                       curlen = min((unsigned long)len,
+                                    0x400000 - (from & (0x400000 - 1)));
+                       memcpy(to,
+                              (void *)((from & ~0xc00000) |
+                                       ((((from >> 22) + shift) & 3) << 22)),
+                              curlen);
+                       len -= curlen;
+                       from += curlen;
+                       to += curlen;
+               }
+               return;
+       }
+#ifdef __BIG_ENDIAN
+       if (bdipsw == 0) {
+               /* BOOT Mode: Monitor ROM */
+               while (len) {
+                       curlen = min((unsigned long)len,
+                                    0x400000 - (from & (0x400000 - 1)));
+                       memcpy(to, (void *)(from ^ 0x400000), curlen);
+                       len -= curlen;
+                       from += curlen;
+                       to += curlen;
+               }
+               return;
+       }
+#endif
+       memcpy(to, (void *)from, len);
+}
+
+static void rbtx4939_flash_map_init(struct map_info *map)
+{
+       map->read = rbtx4939_flash_read16;
+       map->write = rbtx4939_flash_write16;
+       map->copy_from = rbtx4939_flash_copy_from;
+}
+
+static void __init rbtx4939_mtd_init(void)
+{
+       static struct {
+               struct platform_device dev;
+               struct resource res;
+               struct rbtx4939_flash_data data;
+       } pdevs[4];
+       int i;
+       static char names[4][8];
+       static struct mtd_partition parts[4];
+       struct rbtx4939_flash_data *boot_pdata = &pdevs[0].data;
+       u8 bdipsw = readb(rbtx4939_bdipsw_addr) & 0x0f;
+
+       if (bdipsw & 8) {
+               /* BOOT Mode: USER ROM1 / USER ROM2 */
+               boot_pdata->nr_parts = 4;
+               for (i = 0; i < boot_pdata->nr_parts; i++) {
+                       sprintf(names[i], "img%d", 4 - i);
+                       parts[i].name = names[i];
+                       parts[i].size = 0x400000;
+                       parts[i].offset = MTDPART_OFS_NXTBLK;
+               }
+       } else if (bdipsw == 0) {
+               /* BOOT Mode: Monitor ROM */
+               boot_pdata->nr_parts = 2;
+               strcpy(names[0], "big");
+               strcpy(names[1], "little");
+               for (i = 0; i < boot_pdata->nr_parts; i++) {
+                       parts[i].name = names[i];
+                       parts[i].size = 0x400000;
+                       parts[i].offset = MTDPART_OFS_NXTBLK;
+               }
+       } else {
+               /* BOOT Mode: ROM Emulator */
+               boot_pdata->nr_parts = 2;
+               parts[0].name = "boot";
+               parts[0].offset = 0xc00000;
+               parts[0].size = 0x400000;
+               parts[1].name = "user";
+               parts[1].offset = 0;
+               parts[1].size = 0xc00000;
+       }
+       boot_pdata->parts = parts;
+       boot_pdata->map_init = rbtx4939_flash_map_init;
+
+       for (i = 0; i < ARRAY_SIZE(pdevs); i++) {
+               struct resource *r = &pdevs[i].res;
+               struct platform_device *dev = &pdevs[i].dev;
+
+               r->start = 0x1f000000 - i * 0x1000000;
+               r->end = r->start + 0x1000000 - 1;
+               r->flags = IORESOURCE_MEM;
+               pdevs[i].data.width = 2;
+               dev->num_resources = 1;
+               dev->resource = r;
+               dev->id = i;
+               dev->name = "rbtx4939-flash";
+               dev->dev.platform_data = &pdevs[i].data;
+               platform_device_register(dev);
+       }
+}
+#else
+static void __init rbtx4939_mtd_init(void)
+{
+}
+#endif
+
 static void __init rbtx4939_arch_init(void)
 {
        rbtx4939_pci_setup();
@@ -333,6 +489,7 @@ static void __init rbtx4939_device_init(void)
            platform_device_add_data(pdev, &smc_pdata, sizeof(smc_pdata)) ||
            platform_device_add(pdev))
                platform_device_put(pdev);
+       rbtx4939_mtd_init();
        /* TC58DVM82A1FT: tDH=10ns, tWP=tRP=tREADID=35ns */
        tx4939_ndfmc_init(10, 35,
                          (1 << 1) | (1 << 2),
-- 
1.5.6.3


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